This invention relates generally to ambulatory medical systems that include a medical device and a control device that communicate via telemetry and more particularly to devices that exchange messages using a robust telemetry protocol. Preferred embodiments relate to implantable infusion pumps and external devices for communicating therewith.
Various ambulatory medical devices have been proposed and a number of such devices are commercially available. These devices include, for example, implantable infusion pumps, externally carried infusion pumps, implantable pacemakers, implantable defibrillators, implantable neural stimulators, implantable physiological sensors, externally carried physiologic sensors, and the like.
Numerous electronic devices exist that communicate with one another using electromagnetic radiation of various wavelengths and of various formats. These electronic devices can act as sources of interference that can negatively impact other devices that also need to communicate via telemetry. This is particularly true when other devices attempt to communicate using small signal strengths that are typically associated with the limited power that is available to ambulatory medical devices and most particular to ambulatory devices that are implanted within the body of a patient.
As appropriate operation of medical devices may be critical to those patients being treated using those devices, and as telemetry communications between medical devices and external controllers can greatly enhance the convenience of using such devices, or even be an enabling necessity to the use of such devices (e.g. implantable devices with sophisticated functionality), the operation of such medical devices can benefit significantly by use of telemetry systems and protocols that have features/elements that lead to optimization of various attributes. Attributes of interest may vary with circumstance but some attributes of general interest include (1) flexibility in communicating the wide variety signals that may be useful to controlling and retrieving information from a sophisticated medical device, (2) robustness in distinguishing actual signals from noise, (3) robustness in distinguishing valid signals from corrupt signals, (4) robustness in ascertaining when appropriate communication has occurred and when additional communication must be attempted, (5) a reasonable efficiency in communication time, and/or (6) a reasonable efficiency in electrical power consumption associated with conveying information over the telemetry system.
For example, implantable infusion pumps are generally configured to accept infusion commands from an external communication device via an RF telemetry system, or the like. These commands may be used, inter alia, to set program variables that are in turn used in defining the quantity and/or timing that is used in supplying a drug to the patient. As the dispensing of appropriate amounts of the drug may be critical to the patient""s well being, it is desirable that a reliable and trustworthy communication channel exist between the external communication device and the implantable device so that messages from the external communication device requesting drug delivery are received with integrity, confirmation of accurate reception acknowledged in a rapid manner, and minimal electric power consumption occurring in the entire process of listening for a message, receiving the message, and transmitting a response to the message that is appropriately received by the external communication device.
Implantable medical devices typically operate by battery power. The batteries may or may not be rechargeable. Higher consumption of power from an implantable medical device containing non-rechargeable batteries leads to a shortening of the usable life of the device and an associated increased frequency of surgery, potential pain, recovery, and inconvenience. Higher consumption of power from an implantable medical device containing rechargeable batteries leads to more frequent charging periods for the batteries and associated inconvenience and may lead to an overall shortening of the usable life of the device. As such, whether or not an implantable medical device contains rechargeable batteries or non-rechargeable batteries, it is desirable to lower the power consumption of the device. As telemetry reception and transmission are highly energy consumptive, it is desirable to minimize the operation time of telemetry reception and transmission modules. As such it is desirable to ensure that message length is kept to a minimum and that repeated transmissions and attempted receptions of previously sent but unsuccessfully received messages be kept to a minimum.
A need exists in the field for improved telemetry features/elements that tend to optimize each of the above noted attributes individually, with out consideration of the impact on other attributes, or tend to simultaneously optimize groups of selected attributes, or tend to provide a balance between various ones of the attributes.
It is a first object of certain aspects of the invention to enhance the ability to communicate a wide variety signals that are useful in controlling and retrieving information from an ambulatory medical device.
It is a second object of certain aspects of the invention to enhance the robustness of distinguishing actual signals from when receiving telemetry communications in an ambulatory medical system.
It is a third object of certain aspects of the invention to enhance the robustness of distinguishing valid signals corrupt signals when receiving telemetry communications in an ambulatory medical system.
It is a fourth object of certain aspects of the invention to enhance the robustness of ascertaining when appropriate communication has occurred and when additional communication must be attempted in an ambulatory medical system.
It is a fifth object of certain aspects of the invention to decrease the time that is spent in transmitting and receiving messages using a telemetry system in an ambulatory medical system.
It is a sixth object of certain aspects of the invention to decrease the electrical power consumption associated with conveying a given amount of information via telemetry in an ambulatory medical system.
Other objects and advantages of various aspects of the invention will be apparent to those of skill in the art upon review of the teachings herein. The various aspects of the invention set forth below as well as other aspects of the invention not specifically set forth below but ascertained from the teachings found herein, may address the above noted objects or other objects ascertained from the teachings herein individually or in various combinations. As such, it is intended that each aspect of the invention address at least one of the above noted objects or address some other object that will be apparent to one of skill in the art from a review of the teachings herein. It is not intended that all, or even a portion of these objects, necessarily be addressed by any single aspect of the invention even though that may be the case with regard to some aspects.
A first aspect of the invention provides a medical system that includes (a) an ambulatory medical device (MD) that includes MD electronic control circuitry that further includes at least one MD telemetry system and at least one MD processor that controls, at least in part, operation of the MD telemetry system and operation of the medical device, wherein the medical device is configured to provide a treatment to a body of a patient or to monitor a selected state of the body; and (b) a communication device (CD) that includes CD electronic control circuitry that further includes at least one CD telemetry system and at least one CD processor that controls, at least in part, operation of the CD telemetry system and operation of the communication device, wherein the CD telemetry system sends messages to or receives messages from the MD telemetry system, wherein at least a portion of the messages transmitted between the communication device and the medical device are transmitted using a message structure that includes a preamble, a telemetry identifier, and data.
In a specific variation of the first aspect of the invention, the CD telemetry system sends messages to the MD telemetry system using a message structure that comprises: (1) an MD preamble, (2) an MD telemetry identifier, (3) MD data including an op-code, and (4) an MD validation code.
In another specific variation of the first aspect of the invention, the MD telemetry system sends messages to the CD telemetry system using a message structure that comprises: (1) a CD preamble, (2) a CD telemetry identifier, (3) CD data including a CD op-code, and (4) a CD validation code.
A second aspect of the invention provides a medical system that includes (a) an ambulatory medical device (MD) that includes MD electronic control circuitry that further includes at least one MD telemetry system and at least one MD processor that controls, at least in part, operation of the MD telemetry system and operation of the medical device, wherein the medical device is configured to provide a treatment to a body of a patient or to monitor a selected state of the body; and (b) a communication device (CD) that includes CD electronic control circuitry that further includes at least one CD telemetry system and at least one CD processor that controls, at least in part, operation of the CD telemetry system and operation of the communication device, wherein the CD telemetry system sends messages to or receives messages from the MD telemetry system, wherein at least a portion of the messages sent between the communication device and the medical device are directed to specific medical device, or a specific communication device, by inclusion of an MD identifier that identifies the medical device or a CD identifier that identifies the communication device.
A third aspect of the invention provides a medical system that includes (a) an ambulatory medical device (MD) that includes MD electronic control circuitry that further includes at least one MD telemetry system and at least one MD processor that controls, at least in part, operation of the MD telemetry system and operation of the medical device, wherein the medical device is configured to provide a treatment to a body of a patient or to monitor a selected state of the body; and (b) a communication device (CD) that includes CD electronic control circuitry that further includes at least one CD telemetry system and at least one CD processor that controls, at least in part, operation of the CD telemetry system and operation of the communication device, wherein the CD telemetry system sends messages to or receives messages from the MD telemetry system, wherein the integrity of at least a portion of a message passed between the communication device and medical device is confirmed by analysis of a predefined interrelation between at least two portions of the message.
A fourth aspect of the invention provides a medical system that includes (a) an ambulatory medical device (MD) that includes MD electronic control circuitry that further includes at least one MD telemetry system and at least one MD processor that controls, at least in part, operation of the MD telemetry system and operation of the medical device, wherein the medical device is configured to provide a treatment to a body of a patient or to monitor a selected state of the body; and (b) a communication device (CD) that includes CD electronic control circuitry that further includes at least one CD telemetry system and at least one CD processor that controls, at least in part, operation of the CD telemetry system and operation of the communication device, wherein the CD telemetry system sends messages to or receives messages from the MD telemetry system, wherein at least one of the medical device or the communication device acts as a sender to transmit a message to the other of the communication device or the medical device, which is the intended receiver of the message, wherein the message is sent with a validation code that is derived in part from the content of the message and in part from other information not explicitly transmitted in the message, and wherein the other information is known in advance by the receiver and is used by the receiver in determining that the message was received without error.
A fifth aspect of the invention provides a medical system that includes (a) an ambulatory medical device (MD) that includes MD electronic control circuitry that further includes at least one MD telemetry system and at least one MD processor that controls, at least in part, operation of the MD telemetry system and operation of the medical device, wherein the medical device is configured to provide a treatment to a body of a patient or to monitor a selected state of the body; and (b) a communication device (CD) that includes CD electronic control circuitry that further includes at least one CD telemetry system and at least one CD processor that controls, at least in part, operation of the CD telemetry system and operation of the communication device, wherein the CD telemetry system sends messages to or receives messages from the MD telemetry system, wherein a message is sent using one of a predefined plurality of preambles.
A sixth aspect of the invention provides a medical system that includes (a) an ambulatory medical device (MD) that includes MD electronic control circuitry that further includes at least one MD telemetry system and at least one MD processor that controls, at least in part, operation of the MD telemetry system and operation of the medical device, wherein the medical device is configured to provide a treatment to a body of a patient or to monitor a selected state of the body; and (b) a communication device (CD) that includes CD electronic control circuitry that further includes at least one CD telemetry system and at least one CD processor that controls, at least in part, operation of the CD telemetry system and operation of the communication device, wherein the CD telemetry system sends messages to or receives messages from the MD telemetry system, wherein the communication device has a CD telemetry identifier and the medical device has a MD telemetry identifier wherein the length of the CD telemetry and MD telemetry identifiers are different.
A seventh aspect of the invention provides a medical system that includes (a) an ambulatory medical device (MD) that includes MD electronic control circuitry that further includes at least one MD telemetry system and at least one MD processor that controls, at least in part, operation of the MD telemetry system and operation of the medical device, wherein the medical device is configured to provide a treatment to a body of a patient or to monitor a selected state of the body; and (b) a communication device (CD) that includes CD electronic control circuitry that further includes at least one CD telemetry system and at least one CD processor that controls, at least in part, operation of the CD telemetry system and operation of the communication device, wherein the CD telemetry system sends messages to or receives messages from the MD telemetry system, wherein the MD telemetry system is configured to perform a bit pattern recognition that allows a selected level of fault tolerance in concluding that a selected portion of a message matches an expected pattern to be received.
A eighth aspect of the invention provides a medical system that includes (a) an ambulatory medical device (MD) that includes MD electronic control circuitry that further includes at least one MD telemetry system and at least one MD processor that controls, at least in part, operation of the MD telemetry system and operation of the medical device, wherein the medical device is configured to provide a treatment to a body of a patient or to monitor a selected state of the body; and (b) a communication device (CD) that includes CD electronic control circuitry that further includes at least one CD telemetry system and at least one CD processor that controls, at least in part, operation of the CD telemetry system and operation of the communication device, wherein the CD telemetry system sends messages to or receives messages from the MD telemetry system, wherein at least one of the MD telemetry system or the CD telemetry system is configured to establish bit synchronization using bit information transmitted in a preamble portion of a message and uses a different pattern to establish synchronization for groups of bits.
An ninth aspect of the invention provides a medical system that includes (a) an ambulatory medical device (MD) that includes MD electronic control circuitry that further includes at least one MD telemetry system and at least one MD processor that controls, at least in part, operation of the MD telemetry system and operation of the medical device, wherein the medical device is configured to provide a treatment to a body of a patient or to monitor a selected state of the body; and (b) a communication device (CD) that includes CD electronic control circuitry that further includes at least one CD telemetry system and at least one CD processor that controls, at least in part, operation of the CD telemetry system and operation of the communication device, wherein the CD telemetry system sends messages to or receives messages from the MD telemetry system, wherein at least one of the MD telemetry system or the CD telemetry system is configured to establish frame synchronization and to confirm that a message is intended specifically for the medical device or the communication device, respectively, by confirming receipt of a predefined identifier.
An tenth aspect of the invention provides a medical system that includes (a) an ambulatory medical device (MD) that includes MD electronic control circuitry that further includes at least one MD telemetry system and at least one MD processor that controls, at least in part, operation of the MD telemetry system and operation of the medical device, wherein the medical device is configured to provide a treatment to a body of a patient or to monitor a selected state of the body; and (b) a communication device (CD) that includes CD electronic control circuitry that further includes at least one CD telemetry system and at least one CD processor that controls, at least in part, operation of the CD telemetry system and operation of the communication device, wherein the CD telemetry system sends messages to or receives messages from the MD telemetry system, wherein selected messages sent between the MD telemetry system and the CD telemetry system comprise character patterns that are incremented in relationship to corresponding character patterns included in one or more previous messages.
In a specific variation of the tenth aspect of the invention, the character patterns are sequence numbers that are varied between first and second messages that are varied within a receiver when they are successfully received and varied within a transmitter when the transmitter receives confirmation that the message was successfully received.
A eleventh aspect of the invention provides a medical system that includes (a) an ambulatory medical device (MD) that includes MD electronic control circuitry that further includes at least one MD telemetry system and at least one MD processor that controls, at least in part, operation of the MD telemetry system and operation of the medical device, wherein the medical device is configured to provide a treatment to a body of a patient or to monitor a selected state of the body; and (b) a communication device (CD) that includes CD electronic control circuitry that further includes at least one CD telemetry system and at least one CD processor that controls, at least in part, operation of the CD telemetry system and operation of the communication device, wherein the CD telemetry system sends messages to or receives messages from the MD telemetry system, wherein the communication device requires pre-knowledge of a telemetry identifier for the medical device prior to sending any messages to the medical device that can be used by the medical device to significantly modify the medical functioning of the medical device, or wherein the medical device requires pre-knowledge of a telemetry identifier for the communication device prior to the medical device accepting any messages from the communication device that can be used by the medical device to significantly modify the medical functioning of the medical device.
A twelfth aspect of the invention provides a medical system that includes (a) an ambulatory medical device (MD) that includes MD electronic control circuitry that further includes at least one MD telemetry system and at least one MD processor that controls, at least in part, operation of the MD telemetry system and operation of the medical device, wherein the medical device is configured to provide a treatment to a body of a patient or to monitor a selected state of the body; (b) a communication device (CD) that includes CD electronic control circuitry that further includes at least one CD telemetry system and at least one CD processor that controls, at least in part, operation of the CD telemetry system and operation of the communication device, wherein the CD telemetry system sends messages to or receives messages from the MD telemetry system; and (c) a second device (SD) including at least one infrared SD communication system, wherein the and CD telemetry system and the MD telemetry system are RF telemetry systems, and wherein the communication device further comprises an infrared CD communication system for sending messages to or receiving messages from the SD communication system.
A thirteenth aspect of the invention provides a medical system that includes (a) an ambulatory medical device (MD) that includes MD electronic control circuitry that further includes at least one MD telemetry system and at least one MD processor that controls, at least in part, operation of the MD telemetry system and operation of the medical device, wherein the medical device is configured to provide a treatment to a body of a patient or to monitor a selected state of the body; (b) a communication device (CD) that includes CD electronic control circuitry that further includes at least one CD telemetry system and at least one CD processor that controls, at least in part, operation of the CD telemetry system and operation of the communication device, wherein the CD telemetry system sends messages to or receives messages from the MD telemetry system, wherein a message is sent by the communication device to the medical device using a first frame synchronization pattern and wherein a message sent by the medical device to the communication device is sent with a second frame synchronization pattern which is different from the first pattern.
Additional specific variations, provide the medical devices of each of the above aspects and above noted variations as implantable devices such as implantable infusion pumps, implantable physiological sensors, implantable stimulators, and the like, or external devices such as subcutaneous delivery infusion pumps or sensors that ascertain a physiological parameter or parameters from subcutaneous tissue or from the skin of the patient. Such infusion pumps may dispense insulin, analgesics, neurological drugs, drugs for treating AIDS, drugs for treating chronic ailments or acute ailments. Sensors may be used to detect various physiological parameters such as hormone levels, insulin, pH, oxygen, other blood chemical constituent levels, and the like. The sensor may be of the electrochemical type, optical type, and may or may not be enzymatic in operation.
In even further variations of the above noted aspects, and above noted variations, one or more of the following is provided: (1) a first portion of the MD telemetry system is incorporated into the MD processor and a second portion of the MD telemetry system is external to the MD processor, (2) a first portion of the CD telemetry system is incorporated into the CD processor and a second portion of the CD telemetry system is external to the CD processor, (3) the MD processor includes an MD central processing unit and at least one other MD functional module, (4) the CD processor includes a CD central processing unit and at least one other CD functional module, (5) the MD electronic control circuitry includes at least one external MD functional module, other than a portion of the MD telemetry system, that is external to the MD processor, or (6) the CD electronic control circuitry includes at least one external CD functional module, other than a portion of the CD telemetry system, that is external to the CD processor.
Still additional aspects of the invention set forth method counterparts to the above system aspects as well as to other functional associations and relationships, and processes that have not been specifically set forth above but will be understood by those of skill in the art from a review of the teachings provided herein.
Further aspects of the invention will be understood by those of skill in the art upon reviewing the teachings herein. These other aspects of the invention may provide various combinations of the aspects presented above as well as provide other configurations, structures, functional relationships, and processes that have not been specifically set forth above.